Permattunement
A form of attunement, which once performed, cannot be easily undone, or undone at all. The item will be permanently attuned to a specific character can cannot be un-attuned, or may not even be tradable. Common in MMOs to stop powerful secondhand equipment from being sold or traded after the primary owner no longer needs it, preventing a flood of used equipment from entering the market.
A variation for MMOs is to allow the item to be traded to and equipped by other characters on the player’s account.